1. Field of the Invention
This invention relates to a system for sealing off sections of a pipe. More particularly, this invention relates to a separating and sealing system for isolating a first section of a submerged pipeline from a second section of the submerged pipeline.
2. Description of the Prior Art
In the offshore production of oil and gas, pipelines are used to transport produced hydrocarbons to onshore storage and refining facilities. Typically, the pipelines are connected offshore to a platform, temporary surface storage facility or a submerged production system. The pipeline may be attached directly to the structure or to a distribution manifold or a satellite tree.
Occasionally, in maintaining the pipelines it is necessary to check the pressure integrity of the pipeline or a section of the pipeline. One method to accomplish such a check is to divide and seal the pipeline into a series of sections by means of a pressure-moveable plug member commonly referred to as a "pig means" (see U.S. Pat. Nos. 3,561,490; 3,903,730; and 4,077,435). Pressure may then be introduced sequentially into each section to check for leaks. However, for specific applications such as sealing a section of a pipeline which has a bend with a very small radius of curvature, the use of such conventional pig means may be difficult. In addition, the pig means disclosed in U.S. Pat. Nos. 3,561,490 and 4,077,435 are complicated and expensive to manufacture and maintain.
Therefore, the need exists for an improved system for separating and sealing a pipeline which is simple to manufacture and maintain and which is capable of passing through pipelines having unusual geometric configurations or operating requirements.